The present invention relates to a radioactive waste processing method, especially to a processing system for radioactive waste resin, condensed waste liquid, incinerated ashes, and non-burnable miscellaneous solid bodies etc.
Hitherto, as for solidification technique, cement solidification (JP Appl. No. 62-124872 (1987)) and plastic solidification (JP Appl. No. 62-268055 (1987)) have been used. As for methods for solidification process, JP Appl. No. 63-33541 (1988), JP Appl. No. 63-11687 (1988) were disclosed. The above described methods for solidification have been established, and packages having superior integrity can be, actually have been, prepared by the above described methods,. As storage in land becoming concrete, measurement of exact inventory of radioactivity per a package has become a problem. Accordingly, research on transportation managing system has progressed in order to measure radioactivity per a package which is processed by the solidification process, and measuring methods have been disclosed in JP Appl. No. 61-26345 (1986) and JP Appl. No. 2-157340 (1990). Farther, a method wherein radioactivity of nuclides other than Co-60 and Cs-137 are estimated by evaluating safety factor higher than radioactivity of Co-60 and Cs-137 (scaling factor method) is going to be applied to transportation management. However, reproducibility of correlation between Co-60, Cs-137, and other nuclides, which is one of fundamentals of the scaling factor, is not so well established, and accordingly, the correlation obtained by experiments or actual measurement is multiplied by 10-100 as a safety factor in actual use. That means, the above described method evaluates the correlation in safety side as much, but there is a possibility to overestimate the radioactivity of a package.
By the above described conventional technique, it was difficult to grasp exactly sort and quantity of nuclides in a package even though total approximate inventory of the radioactivity per a package could be grasped. And, by the scaling factor method, radioactivity was evaluated in safety side more than necessity, and there was such a problem that actually transportable package was reprocessed or kept in storing at the site. All the above mentioned problems are caused by a fact that exact grasp of radioactivity and sort of contained nuclides per a package was impossible.